Introduction E-mail:
[email protected] Longitudinal studies help move researchers closer to understanding determinants and mediators of maturation, physical activity (PA) and adiposity. MATURATION LEVEL IN ADOLESCENTS: EFFECTS ON BODY COMPOSITION AND PHYSICAL ACTIVITY CHANGES Benítez-Porres J.1, Alvero-Cruz J.R.2, Moore J.B.3, Carnero E.A.1 1. Biodynamic and Body Composition Laboratory. University of Malaga. Spain 2. Exercise Physiology Laboratory. University of Malaga. Spain. 3. Department of Health Promotion, Education, and Behavior. University of South Carolina. USA. Javier Benítez Porres -University of Málaga, Spain Results An interaction between PA and maturation was statically significant (P<0.05). A non-significant trend was observed between three stages of change with a progressive reduction of FMP across the three stages of change in maturation level (C0 = 0.275±2.70%; C1= -1.490±1.10%; C2= -6.417±2.57%; pairwise comparisons: C0 - C2 = 6.69%, P=0.081 and C1-C2 = 4.93%, P=0.080). Purpose The aim of this study was to longitudinally explore the influence of maturation on PA and adiposity changes in adolescents. Methods Eighty healthy adolescents (42 girls and 38 boys) were followed over three academic years. A PA score was estimated using the Physical Activity Questionnaire (PAQA). Fat mass percentage (FMP) was assessed by anthropometric measurements.Sexual maturity was estimated by percentage of predicted adult stature and adolescents were classified into three changes groups: C0, change from on time to late maturation; C1, no change; C2, change from late/on time to on time/early maturation. A stepwise linear regression was conducted in order to estimate the predictors of PA and FMP changes. Acknowledgments This work was supported by the Spanish Ministry of Education, Culture and Sport (AP2010-0583); Spanish Ministry of Economy and Competitiveness (DEP2011-30565); and University of Málaga (Campus of International Excellence Andalucía Tech). Conclusions Our results suggest that body composition changes observed during adolescence are not driven by changes in PA. PA alteration patterns were influenced by maturation but not by sex. References •International Society for The Advancement In Kinanthropometry (2001). International Standards for Anthropometric Assessment.Australia: ISAK. •Malina, R. M., Bouchard, C., & Bar-Or, O. (2004). Growth, maturation, and physical activity.Champaign, IL: Human Kinetics. •Reilly, J. J., & Kelly, J. (2011). Long-term impact of overweight and obesity in childhood and adolescence on morbidity and premature mortality in adulthood: systematic review. International Journal of Obesity, 35(7), 891-898. 2. •Slaughter, M. H., Lohman, T. G., Boileau, R. A., Horswill, C. A., Stillman, R. J., Van Loan, M. D., & Bemben, D. A. (1988). Skinfold equations for estimation of body fatness in children and youth.Hum Biol,60(5), 709-723. Table I. Comparison of characteristics of participants at baseline and years 1 and 2by sex (n=80). Figure 1. Changes in fat mass percentage after a 2-year follow-up across change in maturation status. S1 S2 S3 S1-S2 S2-S3 Girls Boys Girls Boys Girls Boys sig. sig. Age (years) 14.5±1.8 14.6±2.6 14.8±1.7 15.1±2.4 16.2±1.6 16.1±2.3 ††† ††† Weight (Kg) 52.1±12.7 55.4±12.2 52.4±12.1* 59.6±12.8 54±11.3** 60.8±10.1 ††† Height (cm) 157.5±7.1 162.4±13.7 159.5±7.0** 166.2±11.7 161.1±6.1*** 168.7±10.7 ††† ††† §§ BMI (Kg/m2) 20.9±4.5 20.8±3.0 20.4±3.7 21.4±3.1 20.8±4.0 21.3±2.5 ††† FMP (%) 25.6±7.0* 21.0±8.9 24.6±6.8** 19.5±8.0 25.5±6.8*** 18.2±7.6 §§ Predicted adult stature (cm) 162.5±5.0*** 172.9±6.9 164.3±4.5*** 173.8±5.6 163.9±5.2*** 173.5±5.4 Predicted adult stature (%) 97.1±4.4* 93.5±9,3 97.2±4.1 95.5±8.4 98.6±2.3 97±6.8 ††† §§§ ††† §§§ PA Total Score (PAQA) 2.3±0.9** 2.8±0.7 2.2±0.6*** 3.0±0.6 2.1±0.7** 2.6±0.6 ††† §§§ FFQ variables Carbohydrate (%) 44.7±6.8 46.6±5.8 - - 45.8±7.2 46.5±6.7 Protein (%) 15.4±3.1 14.3±2.4 - - 15.7±4.2 15.1±3.9 Fat (%) 39.7±6.7 39±5.6 - - 38.4±5.3 38.1±6.0 Energy (kcal/day) 3186±1540 3427±1757 - - 2197±998 2565±1501 ‡‡‡ Note: S1, S2, S3 (September 2011, 2012 and 2013 respectively); BMI, Body mass index; FMP, Fat Mass Percent; PA, Physical activity; FFQ, Food frequency questionnaire. * P<0.05; ** P<0.01, *** P<0.001; independent sample t test between boys and girls. ††† P<0.001; repeated measures among three moments (time factor). §§ P<0.01; §§§ P<0.001; interaction between time and sex.
